Propeller control system



s, 1 J. H. HAMMOND, JR ,38

PR PELLER common SYSTEM I Filed Sept. 23, 1941 2 Sheets-Sheet;

'JOHNJ'IAYS HAMMOND, JR.

June 8,' 1943. J. H. HAMMOND, JR

' PROPELLER CONTROL SYSTEM Filed Sept. 23, 1941 2 Sheets-Sheet? TILV INVENTOR JOHN HAYS HAM.M OND,JR.

Patented June 8, 1 943 UNITED, STATES PATENT OFFICE 2,321,381 PROPELLER CONTROL SYSTEM John Hays Hammond, Jr., Gloucester, Mass. I Application September 23, 1941, Serial No. 411,943

6 Claims. (01. 170-1351;)

This invention relates to variable pitch propellers and more specifically to means for varying the pitch of a propeller in accordance with the integrated value, over a definite period of an one original features of construction andcombinations of parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be par-' ticularly pointed out in the claims appended hereto, the invention itself, as to it objects and advantages, the mode of its operation and the manner of its organization may be better understood by referring to the following description, taken in connection with the. accompanying drawings forming a part thereof, in which Figure lillustrates diagrammatically the system for controlling the propeller pitch by means of the thrust of the propeller shaft; Figure 2i1lustrates diagrammatically the system for controlling the propeller pitch by means of the speed of the vessel and; Figure 3 illustrates diagrammatically the system for controlling the propeller pitch by means of the steam consumption of the prime mover.

Like reference characters denote like parts in the several figures of the drawings.

Inthe following description and in the claims parts will be identified by specific names for convenience, but. they are intended to be as generic in their application to similar parts as the art will permit.

Referring to the accompanying drawings, and more particularly to Figure 1, the hull of a marine vessel is indicated as II. This vessel is driven by means of a propeller l2 which is provided with adjustable blades l3. The propeller I2 is attached to the end of a hollow shaft .l5 which passes through an outboard bearing l6 and a The shaft I5 is driven by a thrust bearing ll. prime mover 20 which may be of any desiredtype and is preferably provided-with a governor for maintaining a constant speed of rotation.

The blades I3 are connected to a variable pitch 5:;

mechanism l8 which may be of any'well known and standard construction such as that manufactured by the Escher Wyss Company of Zurich,

Switzerland, the details of which formno part of the present invention and are accordingly notspecifically set forth herein. This mechanism, in general, comprises a rod l9 slidable longitudinally within the shaft I5 and connected to control the pitch of the blades l3."

The rod is is actuated by a piston 21 in a fluid pressure cylinder 21a. Fluid for actuating the piston 21 is supplied by a pump 26 through a control valve and a distribution valve 25a which communicates with the cylinder. 2111 through ducts, not shown, in the shaft IS. A motor 2| rotates a worm 22 which operates to move the upperend of a. floating lever 23, which, in turn, is pivoted to the end of valve rod 24 which controls the valve 25. The piston 2'! isconnected by a rod 28 to a collar 29 which is slidably mounted on the shaft [5 and engages the lower end of thelever 23 so'that the position of this end of-- the lever corresponds to the l3.-

The upper end of the lever 23 is connected by a rod 30 to an indicator 3| which shows the pitch at which the blades i3 are set. Stops 32 are provided for limiting the maximum and minimum pitch of the blades l3. The fluid pump 26 is driven either by'a motor 33 or a belt 35 from the shaft |5.; A reservoir 36 and a supply tank 31 are provided for the'necessary fluid. It is to be understood that other pitch control devices may be employed in place of that pitch of the blades referred to above, for varying the pitch of the propeller blades la in response to actuation of the motor 2|. A particular type is shown for purposes .of illustration only. p Q

The thrust bearing I1 is also struction and only so much thereof has been shown as is necessary to an understanding of this invention. Inthe form shown the thrust bearing is provided with the usual collar 40 and shoe 4| which is engaged by thrust pins 42, which. in turn cooperate with piston pins 43, the'outer ends of which are engaged by pistons which reciprocate in cylinders 46. Mounted on the cylinders 46 are gauges 41 which indicate thetravel of the pistons 45. Fluid under pressurefor operating the'system is suppliedby a manually operated pump which is connected by piping 49 to the cylinders 46 and to a damping valve 59. This valve is connected by a pipe 5| to an indicator 52 which is provided with a. pointer 53 which of standard conregisters with a scale 55 which may be graduated in thousands of pounds thrust;

While the thrust bearing and meter shown is the type manufactured by the Kingsbury Machine -Works of Philadelphia, Pennsylvania, it is to be understood that any other suitable type of thrust bearing and meter may-be employed for the purose. I p In accordance with the present invention,

means is provided for controllin a motor 55 by the position of the pointer 53. In the embodiment shown, this is accomplished by providing a contact 56, attached to, but insulated from, the pointer 53 and a ring 51 surrounding the indicator 52 and rotatably mounted thereon. The ring 5'! carries a segment of worm gear 58. Meshing with the gear 58 is a worm 59 which may be rotated by means of a knurled knob 60. Mounted on but insulated from the ring 51 are a plurality of contact segments 6! to 66 which are selectively engaged by the contact 66.

The segments 6| and 66 are connected by flexible conductors to two conductors I0 and II which in turn are connected to the reversing windings of the motor 55. The segments 62 and 63 are connected by flexible conductors to two resistors 16 and I1, the other ends of which are connected to the conductor 10. The segments 66 and 65 are connected by flexible conductors to two resistors 80 and BI the other sides of which are connected to the conductor H. The return lead from the windings of motor 55 is connected to one side of a battery 82 the other side of which is connected to the blade of a three position switch 83.

The motor 55 is connected thru a reductiongearing 85 toa threaded shaft 06 upon which is mounted a rider 8?. The rider 81 is provided with a pin 88 which engages a slot 86 provided in an L shaped arm 90 which is pivoted for rotation at 9I. Mounted on but insulated from the upper end of arm 90 is a contact 92, which selectively engages two contact segments 95 and 96 which are mounted on but insulated from a memher 9'! which is pivoted for rotation at 91. The lower end of the member 91 is attached to the rod 30. The contacts 95 and 96 are connected to the reversing windings of the motors .2I and to the outside contact points of the switch 83.

A timing device I 00 is provided with a cam IOI which may be rotated at any desired speed, for example, 'one revolution in 20 minutes. Engaging the cam I0! is a roller I02 which is mounted on but insulated from a contact arm I03 which is connected to the center contact point of the switch 83. Mounted adjacent to the contact arm 'is shown as 5,000 pounds.

build up hydraulic pressure in the system, this pressure being indicated by the pointer 63 on the scale 56. After the pressure has been built up sufiiciently behind the pistons 45 it will exert enough pressure through the piston pins 63 and thrust pins 42 to take the entire thrust of the propeller 52. When thi condition ha been reached, as indicated by the gauges 61, the manual operation of the pump 48 is stopped. The thrust of the propeller is now indicated bythe pointer 53 on the scale 54 which in this example The ring 51 is then rotated by means of the knurled knob until insulation between the segments 63 and 64 engages thecontact 56. The blade of the switch 63 is then moved into engagement with the center contact.

If the conditions under which the vessel is travelling should change, such as by encounter- 56, segment 63 and resistor II to the motor 55 causing it to rotate slowly. This motion is further reduced by the reduction gearing so that the threaded shaft 66 causes the rider 81 to move very slowly upward. This motion will continue while the contact 56 is on the segment 63, but will stop if the rider 8! moves far enough to enease the pin I08. The pin I07 and I08 are used to limit the motion of the rider 87' and contact 92.

If the unfavorable conditions increase, the thrust will increase and the contact 56 will en gage the segment 62. The speed of the motor 55 will increase as the current now passes thru the resistor I6, which has less resistance than the resistor IT. This will accelerate the slow upward motion of the rider 81 which will continue at this increased rate while the contact 56 is on the segment 62. If the thrust is further increased so that the contact 56 rests-on the seg- I03 are two contacts I05 and I06, the former being connected by a conductor I09 to the contact 56 and the latter to thecontact 92. Two plus I 01 and I08 are provided for limitting the motion of the rider 81.

Operation of Figure I In the operation of the form of the invention shown in Figure l, the pitch of the blades I3 is set at the normal operating angle for the conditions under which it is desired to operate the vessel. The setting of the propeller blades I3 is accomplished by moving the blade of the switch ment 6I, then no resistance will be thrown in the circuit of the motor 55 and it, will rotate at its maximum speed, thus causing the rider 81 to move upward at its maximum rate, which, however, is still quite slow.

These operations continue for a given period of time, for example 15 minutes. at the end of which the cam I III will have rotated to a position where the roller I02 will drop down on the lower segment of the cam. This will cause the arm I03 to disengage the contact I05 and engage the contact I06, thus opening the circuit thru the motor 55 which will stop.

The position of the rider 81, arm 90 and contact 92 will be proportional to the integrated deviation of the thrust from normal during the 15 minute period and will represent the amount of correction which should be applied to the propeller pitch. As the contact 92 is in engagement with the segment 95 a circuit will be closed from the battery 82 thru arm I03, contact I06, contact 92, segment 95 to the motor 2| causing it to rotate in a direction to move the upper end of the lever 23 to the right. This will move the valve 24 to the right which will allow fluid under pressure to pass from the pump 26 to the cylinder 27;: by means of the ducts in the shaft I5.

' the lever 23 moves to the right it will move the rod 30 to the right which will rotate the member 91 in a counter clockwise direction until the contact 92 rests on the insulation between the segments 95 and 95 thus stopping the motor2I.

' Movement of thepiston 21 and collar'29 to the left shifts the lever 23 to the left until the valve 25 is again in its neutral position to cut on the .further supply of fluid to the cylinder 21a.

The dam IOI will rotate for agiven period, for example five minutes, with the roller I02 on the lower segment. At the end of this time the roller I02 will move onto the upper segment thus raising the arm I03 which will disengage the contact I05 and engage the contact I05. During this five minute interval the condition of propulsion has changed due to the decrease of propeller pitch thus decreasing the thrust to normal. of 5,000, lbs. at which figure the contact 56 will again rest on the insulation between the segments 53 and 54.

With the closing of the contact I05 the circuit from the battery 82 has'been returned'to the motor 55. Now if the thrust should decrease due to a following wind or other favorable conditions, the'reverse action would take place, thus causing the rider 8! to move slowly downward for a period of minutes, the rate of motion being dependshown a contact H9 is attachedto but insulated from the pointer III. Surrounding the speed indicator IIS and rotatably mounted thereon is a ring I to which is attached a segment of a worm gear I2I. Meshing with the gear I2I is a worm I22 which is rotated by means of knurled knob I23. Mounted on but insulated from the ring I20 are a plurality of contact segments I to I which are selectively engaged bythe contact -I I9.

The segments I25 and I30 are connected to the two conductors I and II which in turn are connected to the reversing windings of the motor 55 in a manner similar to that described in connection with Figure 1. I21 are connected to the two resistors I6 and 11, the other'ends of which are connected to'the conductor I0. The segments I23 and I29 are connected to the two resistors 80 and 8I, the other ends of which are connected to. the conductor II. The contact II9 isconnected tothe conductor I09, the other end of which is connected to .the contact I05 shown in Figure 1.

ent on the deviation of the thrust from normal. At the end of this period the motor 55 --would be thrown out of circuit and the motor 2I thrown in circuit by the action of the cam .IOI, as already described. As this time the contact 92 would be on-thesegment 95 the motor 2I would be rotated so .as to moveithe 'upper'end of the lever 23 to the left, thus increasing thepropel lerpitch and at the same time rotating the member 91 in a clockwise direction. This motion will continue until the contact 92 rests on the insulation between the segments 95 and 95 thus stopping the tegrated deviation of thrust, which causes the.

thrust to retumto normal.

The variation of the propeller pitch by the use p of the integrator may also be controlled by the speed of the vessel as shown in Figure 2. In this 'figure a speedometer III is shown as being mounted in the hull of the vessel II. This speedometer may be of any well known and standard construction, such as that-made by the Kenyon Instrument Company of Huntington. Long Island, New York, and known as the-Kenyon speedometer. This comprises a strut I I2 which is attached to a metallic bellows II3 containing fluid under pressure. The bellows I I3 is connected by a hydraulic tube II5 to a speed indicator H6 which is provided with a pointer-III which registers with a scale II9 graduated in knots."- It is to be understood that other types of speed indicating devices may be used if desired.

In accordance with the :present invention means is provided to control the integrator motor 55, shown in Figure 1, in response to the position of the pointer I I1. In the embodiment In this form of the invention the pitch chang-. ingmechanism and integrator are similar to those shown in Figure 1, but the thrust meterJI and indicator 52, together with their associated The segments I25 and parts numbered 40 to 56 have been replaced by the speedometer III and indicator I I5.

Operation of Figure 2 In the operation of the modified form of the invention shown .in- Figure2 the pitch of the blades I3 is set at the normal operating angle 0 for the speed at which itis desired to operate the vessel, which for example may be 25 knots.

The setting of the propeller blades I3 is accomplished in a manner similar to that described in connection with Figure l.

Th vessel is then brought up to the desiredspeed aSindicated by the pointer III on the scale 8, in this case 25 knots. The ring I20 is then rotated by means of the knurled knob I23 until the insulation between the segments I21 and I28 engages the contact II9. The blade oi. the switch 03 (Figure 1) is then moved into engage'ment with the center contact.

If the conditions under which the vessel is travelling should change and the speed of the vessel diminish, the strut II2 will receive'less pres- 7 sure so that the hydraulic cylinder II3 will transmit less pressure to the speed indicator I I5, the-pointer III of which will therefore rotate in a counterclockwise direction to indicate a decrease of speed. The contacti I9 will then engage the segment I29 and a. circuit will be closed thru the resistor 80 and the motor- (Figure 1) which will rotate in such a. direction as to cause the rider 81 to move downwards very slowly. This in a manner already described will cause the contact "to move-to the right. into engagement with the segment 96.

crease thecontact "9 will engage the segment It the speed of the vessel should further de- I29 and the smaller resistance 8| will be thrown into the circuit of the motor 55 thus increasing its speed of rotation, With a still further decrease of speed the contact-I I9 will engage "the segment III at which time no resistance will be I I .in' the circuit of the motor 55, thus causing: it to rotate at its maximum speed.

This action will continue until at the end oi the fifteen minute interval the motor 55 will be thrown out of circuit and the motor 2I thrown in in a manner similar to that described in connction with Figure 1. As the contact 92 is on segment 96 the motor 2| will be rotated so as to cause the arm 23 to be moved to the leit which will cause an increase in the propeller pitch. This action will continue until the member 91 has been sufliciently rotated in a clockwise direction to cause the insulation between the se ments 95 and 96 to engage the contact 92 thus stopping the motor 2I.

The increase of propeller pitch will cause an increase of speed of the vessel, as the propeller revolutions are kept constant by means of the governor, thus bringing the contact II9 back on I the insulation between the segments I21 and I28. At the end of the five minute interval the motor 2I will be thrown out of circuit and the motor 55 thrown in.

terval an amount proportional'to the integrated.

variation of speed from normal over this interval and will cause the propeller to operate so as to 'draw the required power from the prime mover 20 under the changed conditions to maintain the speed of the vessel constant.

' The variation of the propeller pitch by the use of the integrator may also be controlled by the steam consumption of the prime mover as shown in Figure 3. In this figure a fluid meter I35 is shown as being connected to the steam supply line I36 of the prime mover 20, in which is also connected a governor I31.

The fluid meter I35, which may be of any well known and standard construction such as that manufactured by the Bailey Meter Co., of Cleveland, Ohio, and described on pages 9-11 of their bulletin 301, is shown for measuring the volume of steam supplied to engine 20. The meter I35 consists essentially of a box I38 in which is mounted a bell casing I39. Positioned inside of this casing is a mercury sealed Ledoux bell I40, which is free to move up and down inside the casing I39. A cap I, rests on top of the bell I40 and is attached by a forked lever I42 to a spindle I43.

The engine 20 is supplied with steam thru the pipe I36 in which is located an orifice plate I44. The interior of the casing I39 is connected by a tube I45 to a point in the pipe I36 below the orifice plates I44 and the interior of the bell I40 is connected by a tube I46 to a point in the pipe I 36 above the orifice plate I45.

The spindle I43, which passes thru the wall of the casing I39, is connected to an arm I41.

resistors 80 and 8| the other ends of which are connected to the conductor II. The contact I48 is connected to the conductor I89, the other end fluid meter I35.

Operation of Figure 3 In the operation of the modified form of the invention shown in Figure 3 the pitch of the blades I3 is set at the normal operating angle as described in connection with Figure l. The vessel is brought up to the desired speed in the usual manner. supply the engine 20 under these conditions passes thru the orifice in the plate. I44 which causes an increase of pressure in the pipe I46 and a decrease of pressurein the pipe I45. The reduced pressure established in the pipe I45 is applied to the interior of the casing I39 and the increased pressure established in the pipe I46 is applied to the interior of the bell I40. This causes the bell I40 to rise an amount proportional to the difference in pressures in the pipes I45 and I46.

The motionof the bell I40 is transmitted by means of the cap MI and lever I42, to the arm I41 and contact I48 which takes up a position depending upon the difference in pressure inside and outside the bell I40 which is proportional to the volume of steam consumed by the engine 20. The member I56 is then moved until the insulation between the segments I5I and I52 is under the contact I48 and is held in this position by tightening the screw I60. The blade of the switch 82 is then moved into engagement with the center contact.

' If the forces against which the vessel is moving should increase the speed of the propeller I2 would decrease and the throttle valve would be opened by the governor I31 to supply more steam This will close a circuit thru the resistor I1 and V the motor 55 (Figure 1) which will rotate in such Mounted on but insulated from the arm I4! is a tached to a plate "I59 which is secured to the box I38. The bracket I58 is provided with a clamping screw I60 for holding the member I56 and contact I 49-I54 in any desired position.

The segments I49 .and' I54 areconnected to the two'conduc'tors I8 and 1| which in turn are connected to reversing windings of the motor 55,

3 as previously described in connection with Figure 1. The segments I50 and I5I are connected. to the two resistors I6 and 11, the other ends of which are'connected to the conductor I0. The

segments I52 and I53 are connected to the two a direction as to cause the rider to move upward very slowly. This in a manner already described will cause the contact 92 to move to the left into engagement with the segment 95.

be in the circuit of the motor 55 thus causing it to rotate at its maximum speed.

This action will continue until at the end of the fifteen minute interval the motor 55 w ll be thrown out of circuit and the motor 2! thrown,

in in a manner similar to that described in connection with Figure 1. As the contact 92 is on segment 95 the motor 2I will be rotated so as to cause the arm 23 to be moved to the rightwhich will cause a decrease in the propeller pitch. This action will continue until the member 91 has The steam necessary to been suiiiciently rotated in a counter clockwise direction to cause. the insulation between the segments 95 and 96 to engage the contact 92, thus stopping the motor 2!. I

The decrease of propeller pitch will cause a decrease in steam consumption, thus bringing the contact I48 back on the insulation between the segments ISI and l52. At the end of the five minute interval the motor 2| will be thrown out of circuit and the motor 55 thrown in.

If the conditions change so that the steam consumption decreases the reverse action will take place and the pitch of the propellers will be increased at the end of the fifteen minute interval.

In this way the pitch of the propeller blades I3 is varied at the end of each fifteen minute interval an amount proportional to the integrated a predetermined period of time, and timed means actuated after each of said predetermined periods" a variation of steam consumption from normal Although only a few of the various forms in i which this invention may be embodied have been shown herein, it is to be understood that the invention is not limited to-any specific construction but might be embodied in various forms without departing from the spirit of thelnvention or the scope of the appended claims.

What is claimed is:

1. In a system for driving a vessel, a propeller having blades, means controlling the pitch of said blades, condition responsive means responsive to the amount of change of a condition of propulsion of said vessel, means integrating the change of said condition responsive means over to cause said pitch control means to change the pitch of said. blades in a direction and by an amount to compenaste for the integrated change of condition. g

2. The system set forth in claim 1 in which said condition responsive means includes means to actuate said integrating means at a speed proportional to the amount of change in condition in either direction from, a given median point,

the speed 01 actuation being greater when the change of condition is greater and vice versa, re-

gardless of the direction of said change from said,

median point. g

'3. The system set forth in claim 1 in which the condition responsive means is responsive to the thrust of said propeller.

4. The system set forth in claim 1 in which I the condition responsive means comprisesa thrust bearing and indicating means actuated in re-- speed of travel of the vessel through thesurrounding medium. n

6. The system set forth in claim 1 in which the propeller is driven by a steam driven motor and the condition-responsive means is responsive to the steam consumption of said motornver a. predetermined perlod of time.

. JOHN HAYS HAMMOND, JR. 

